Both the cosco-usa.com and toll-free phone service were not working on Tuesday US time. The situation had not improved by the time of writing (8.35am AEST Thursday).
Cosco is the largest dry bulk carrier in China and one of the largest dry bulk shipping operators worldwide.
In a statement released on Wednesday, the company said: "Due to local network breakdown within our America regions, local email and network telephone cannot work properly at the moment. For safety precautions, we have shut down the connections with other regions for further investigations."
Cosco is the 4th largest shipping company. Here's the bit which is impacted (it looks like they segregated it from the rest of the Group) pic.twitter.com/32oRfUYxyo— Kevin Beaumont (@GossiTheDog) 25 July 2018
The Cosco statement said: "So far, all the vessels of our company are operating as normal, and our main business operation systems are performing stably. We are glad to inform you that we have taken effective measures.
"Except for above regions affected by the network problem, the business operation within all other regions will be recovered very soon.
"The business operations in the affected regions are still being carried out, and we are trying best to make a full and quick recovery. We will keep you updated of the latest progress through various channels."